Reinforced rubber mixtures, a process for their preparation and their use

Abstract

A reinforced rubber mixture composed of (A) at least one natural, styrene/butadiene, polybutadiene, polyisoprene, transpolyoctenylene, ethylene/propylene/diene terpolymer and butyl rubber, (B) at least one phenol novolak resin and/or reactive polyphenol, (C) curing agents and, if appropriate, (D) customary additives, wherein the rubber mixture contains, as an additional component (E), at least one polar, chlorine-free rubber in the form of nitrile rubber having a nitrile content of at least 32% or polyurethane rubber in a proportion by weight of 1 to 49% by weight, relative to the total amount of rubber. Process for the preparation thereof and the use of the reinforced rubber mixtures for the production of industrial rubber goods, in particular for the production of antivibration units, rubber sleeves, coatings, conveyor belts and tires.

I claim: 
     
       1. A reinforced rubber mixture composed of (A) at least one natural, styrene/butadiene, polybutadiene, polyisoprene, transpolyoctenylene, ethylene/propylene/diene terpolymer and butyl rubber, (B) at least one phenol novolak resin or reactive polyphenol or both, (C) curing agents and in the optional presence of (D) customary additives, wherein the rubber mixture contains, as an additional component (E), at least one polar, chlorine-free rubber in the form of nitrile rubber having a nitrile content of at least 32% or polyurethane rubber in a proportion by weight of 1 to 49% by weight, relative to the total amount of rubber. 
     
     
       2. The rubber mixture as claimed in claim 1, wherein fillers, vulcanizing agents, accelerators, activators and processing auxiliaries are present as customary additives. 
     
     
       3. The rubber mixture as claimed in claim 1, wherein carbon black is used as a customary additive. 
     
     
       4. The rubber mixture as claimed in claim 1, wherein the polar rubber is present in amounts of 2 to 39% by weight. 
     
     
       5. The rubber mixture as claimed in claim 1, wherein a compound which splits off formaldehyde or methylene groups, an amine resin having free or etherified methylol groups or a mixture thereof is used as the curing agent for the resins. 
     
     
       6. The rubber mixture as claimed in claim 1, wherein condensation products formed from phenol, substituted phenols, polyhydric mononuclear or polynuclear phenols or mixtures thereof and aldehydes are used as novolak resins. 
     
     
       7. The rubber mixture as claimed in claim 6, wherein formaldehyde is used as aldehyde. 
     
     
       8. The rubber mixture as claimed in claim 1, wherein resorcinol or diphenylolpropane, diphenylolmethane or naphthols are used as reactive poly phenols. 
     
     
       9. A process for reinforcing a mixture composed of (A) at least one natural, styrene-butadiene, polybutadiene, polyisoprene, transpolyoctenylene, ethylene-propylenediene terpolymer and butyl rubber, (B) at least one phenol novolak resin or reactive polyphenol or both, (C) curing agents in the optional presence of (D) customary additives, which comprising incorporating into the rubber mixture of the components (A) to (D), as a further component, (E), at least one polar, chlorine-free rubber in the form of nitrile rubber having a nitrile content of at least 32% or polyurethane rubber in a proportion by weight of 1 to 49% by weight, relative to the total amount of rubber and vulcanizing the mixture. 
     
     
       10. The process as claimed in claim 9, wherein the nolvolak is incorporated either above or below its softening point or fusion temperature and is added jointly with, or seperately from, the curing agent. 
     
     
       11. The process as claimed in claim 9, wherein the curing agent is incorporated at the end of the mixing process at temperatures between 80° and 120° C. 
     
     
       12. The process as claimed in claim 9, wherein fillers, vulcanizing agents, accelerators, activators and processing auxiliaries are present as customary additives. 
     
     
       13. The process as claimed in claim 9, wherein carbon black is used as a customary additive. 
     
     
       14. The process as claimed in claim 9, wherein the polar rubber is present in amounts of 2 to 39% by weight. 
     
     
       15. The process as claimed in claim 14, wherein the polar rubber is present in amount of 3 to 30% by weight. 
     
     
       16. The process as claimed in claim 9, wherein a compound which splits off formaldehyde or methylene groups, an amine resin having free or etherified methylol groups or a mixture thereof is used as the curing agent for the resins. 
     
     
       17. The process as claimed in claim 9, wherein condensation products formed from phenol, substituted phenols, polyhydric mononuclear or polynuclear phenols or mixtures thereof and aldehydes are used as novolak resins. 
     
     
       18. The process as claimed in claim 9, wherein resorcinol or diphenylolpropane, diphenylolmethane or naphthols are used as reactive polyphenols. 
     
     
       19. Industrial rubber goods prepared from the vulcanized reinforced rubber mixtures as claimed in claim 1. 
     
     
       20. Rubber goods as claimed in claim 19 in the form of antivibration units, rubber sleeves, conveyor belts and tires.